Answer: Option (D) is correct.
Step-by-step explanation:
Correct Option: All of the above.
In a perfectly competitive market, there are large number of buyers and sellers in a market. Single buyer and single seller won't be able to affect the price of the market.
All the firms in this market scenario selling a standardized product.
Price of the product will be determined by the market forces. In this market, individual firms are generally facing a horizontal demand curve where price is equal to the marginal revenue. Because demand curve is parallel to x-axis and it is perfectly elastic, so there will be no changes in prices if there is a change in a demand.
Profit maximizing condition for the competitive firms is a point where price is equal to the marginal cost.